顺式与反式偶氮苯衍生物分子非线性光学性质理论研究

利用密度泛函理论(DFT)B3LYP/6-31G(d,p)方法优化了一系列顺式与反式偶氮苯衍生物分子,在此基础上结合有限场(FF)方法和密度泛函理论对分子非线性光学(NLO)性质及电子光谱进行了计算分析,结果表明:顺式与反式结构的变化对其偶极矩、分子内电荷分布与转移以及前线轨道跃迁都造成影响,从而影响分子的第一超极化率.同时相对于顺式偶氮苯衍生物分子,反式分子具有较大的二阶非线性光学系数.

The theoretical study on the nonlinear optical property of cis- and trans-azobenzene derivative molecules

Density functional theory (DFT) B3LYP/6-31G(d,p) method was employed to optimize a series of cis- and trans-azobenzene derivative molecules. Based on the obtained stable molecular configuration , the first hyperpolarizabilities and electric spectrum of these molecules were calculated by the finite field (FF) and density-functional theory approach. The results show that the change of cis- and trans- azobenzene derivative molecules in structures has effect on the dipole moment, intramolecular charge transfer, charge distribution and frontier orbital transitions, and thus affecting the molecular first hyperpolarizabilities. Moreover, cis-azobenzene derivative molecules possess larger the first hyperpolarizabilities in comparison with that of trans- azobenzene derivative molecules.